Hardware Manual COMBILOG 1020
95
10.6 Bus Termination
In order to avoid signal reflections on the bus, each bus segment
has to be blanked off at its physical beginning and at its end with
the characteristic impedance. For this purpose, a terminating re-
sistor Rt is installed between the bus leads A and B. In addition to
that the bus lead A is connected via a pull-down resistor Rd to
ground (DataGround) and the bus lead B is connected via a pull-
up resistor Ru to potential (VP). These resistors provide a defined
quiescent potential in case there is no data transmission on the
bus. This quiescent potential is level
high
.
R
R
R
VP (6)
B (3)
A (8)
DGND (5)
bus cable
u
t
d
= 390 2%, at least watt
R
u
R
t
R
d
Ω
= 150 2%, at least watt
Ω
= 390 2%, at least watt
Ω
±
±
±
14
14
14
VP = +5V :
Figure 10.5 Bus termination
Note:
The numbers in brackets in figure 10.5 indicate the pin
number for the connection via the 9-channel D-subminiature plug.
A
B
Prufibus
designation
COMBILOG
terminal
names
Summary of Contents for COMBILOG 1020
Page 1: ...COMBILOG 1020 Datalogger Hardware Manual Version 3 09...
Page 2: ...Hardware Manual COMBILOG 1020 2 Issue 03 11 2005 Technical data are subject to change...
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Page 86: ...Hardware Manual COMBILOG 1020 86 Bild 8 1 Example Master Slave System...
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